fix: PromptNode run raises on empty inputs #6769

	# If you change this name also do it in linting-skipper.yml and ci_metrics.yml
	name: Linting

	on:
	pull_request:
	paths:
	- "**.py"
	- "**/pyproject.toml"

	env:
	PYTHON_VERSION: "3.8"

	jobs:
	mypy:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v4
	with:
	# With the default value of 1, there are corner cases where tj-actions/changed-files
	# fails with a `no merge base` error
	fetch-depth: 0

	- name: Get changed files
	id: files
	uses: tj-actions/changed-files@v40
	with:
	files: \|
	*/.py
	files_ignore: \|
	test/**
	rest_api/test/**

	- uses: actions/setup-python@v4
	with:
	python-version: ${{ env.PYTHON_VERSION }}

	- name: Install Haystack
	run: \|
	pip install ".[all,dev]"

	- name: Mypy
	if: steps.files.outputs.any_changed == 'true'
	run: \|
	mkdir .mypy_cache/
	mypy --install-types --non-interactive ${{ steps.files.outputs.all_changed_files }} --exclude=rest_api/build/ --exclude=rest_api/test/

	pylint:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v4
	with:
	# With the default value of 1, there are corner cases where tj-actions/changed-files
	# fails with a `no merge base` error
	fetch-depth: 0

	- name: Get changed files
	id: files
	uses: tj-actions/changed-files@v40
	with:
	files: \|
	*/.py
	files_ignore: \|
	test/**
	rest_api/test/**

	- uses: actions/setup-python@v4
	with:
	python-version: ${{ env.PYTHON_VERSION }}

	- name: Install Haystack
	run: \|
	pip install ".[all,dev]" pydoc-markdown
	pip install ./haystack-linter

	- name: Pylint
	if: steps.files.outputs.any_changed == 'true'
	run: \|
	pylint -ry -j 0 ${{ steps.files.outputs.all_changed_files }}

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